Art of refining hydrocarbons



Nev. 19, 1929.v FLA. APGAR 1,735,988

ART of" REFINING HYnRocARBoNs Filed March 1o. 1926 '6 M: W ".wZ- SI/v 9 ',g g L f= 1 i 20 6i A' zi f8 yZl/ INVENTOR BY 2 @fm1 gomma/7 Patented Nov. 19, i929 UNITED STATES OFFICE i 'FRANK A APGAB, or EAST CHICAGO, INDrANA, AssIGNOR To sINoLAIR REFINING COMPANY, or NEW YORK, N. Y., A CORPORATION or MAINE Application led March 10, 1928. Serial No. 260,799.

This invention relates to improvements in the vapor phase refining of hydrocarbons and hydrocarbon mixtures; and more particularly relates to improvements in refining operations in which hydrocarbon vapors are passed in contact with an adsorptive catalyst such as fullers earth to separate, by adsorption or polymerization or otherwise, constituents not suitable as components of the reined product.

When hydrocarbon vapors including certain types of unsaturated compounds, for example the di-Olefines, are passed in contact with fullers earth or similar adsorptive catalysts, a polymerization of these unsaturated compounds takes place With resulting formation of polymers of boiling point higher than that of the original compound. This makes possible a separation of such constituents, undesirable as components, of therefined product Without separation of other unsaturated constituents suitable as components of suchl products, and the several advantages of this general method of refining. hydrocarbon vapors have made it of considerable practical importance, in the refining of motor fuel gasoline in particular. As applied to gasoline, this general method makes possible the removal of constituents rendering the product unstable, of bad color or bad odor Without removal of unsaturated'constituents of special value in the product, such as those which have anti-knock properties.

As commonly practiced, this general method has involved charging of a suitable receptacle with a batch of adsorptive catalyst, passing the hydrocarbon vapors through this receptacle-in contact with the adsorptive catalyst until the catalyst has lost its effectiveness, discharging the spent adsorptive catal st, replacing the discharged material wit a fresh charge of the adsorptive catalyst, and so on. l The adsorptive catalyst as initially supplied to the operation, however, is highly active, much more active than it is during the major part of the operation.

This high initial activity and the subsequent decrease in activity of the adsorptive catalyst involved several difficulties. In particular, it makes it difficult toavoid over-treatmentof the hydrocarbon vapors passed in contact with the adsorptive catalyst when fresh, with consequent losses, it makes it diiiicult to maintain uniform operating conditions and it makes it difficult to secure a uniform product. l

The initial activity of the adsorptive catalyst induces over-treatment in at least two Ways. The initial activity itself tends to cause over-treatment. In addition, the polymerization reaction is eXothermic and as a consequence the tendency toward increase in the reaction rate involves a tendency toward temperature increase. This in turn tends to increase the rate at which thereaction proceeds. This tendency toward over-treatment has peculiar disadvantages in the treatment of motor fuel gasoline.

In t'he treatment of hydrocarbon vapors including gasoline components produced by vapor phase cracking, for example, the temperature increase on passage through a body of fresh fullers earth may amount to 'as much as 100 F. or more, and vthis increase in temperature is usually accompanied by an increase in the color of the hydrocarbon vapors escaping from the fullers earth treatment. In the case of hydrocarbon vapor mixtures which have been fractionated to some definite end boiling point, this end boiling point is usually substantially elevated. Apparently, 4these undesirable effects upon the character of the escaping product are due to 'vaporization of polymers formed by the action of the fullers earth with consequent contamination of the escaping vapor mixture. Further, over-treatment tends to cause losses in the separation and removal of constituents suitable and desirable as components of the motor fuel product.

This invention provides an improved method of Operation which reduces to a minimum difficulties due to variations in the activity of the adsorptive catalysts used in this typo of ref'ming operation. rlhe advantages of the invention include improvement in uniformity of operation, improvement in uniformity of product, and improved According to4 the v'present invention, durihg those periods when the refining opera.- tion is interrupted to dischar the spent adsorptive catalystland 'to rep ace the discharged material with fresh material, the

hydrocarbon vapors normally passed through the refining 'operation are -condensed and separately collected and such separately collected untreated hydrocarbdns are passed through the adsorptive .catalyst in addition tothe hydrocarbon vapors normally passed therethrou h when the refining operation is resumed a er thev interruption and during\` .the following period of high initial activity ofthe yfresh adsorptive catalyst supplied to the 'refining operation during the interruption. This addition of such separately collected hydrocarbons to the hydrocarbon vapors normally passed through the adsorpadvantageous manner.

tive catalyst during the period of high initial activity of the adsorptive catalyst increases the velocity of flow of the vapor lmixture through the adsorptive catalyst and thereby decreases the time ofl Contact between he vapors, and the adsorptive catalystV during this eriod, thus counteracting the high initia activity ofthe adsorptive catalyst and avoiding overtreatment of the hydrocarbon vapors and consequent losses. The operation itself is also made more uniform and a more uniform product is secured. The condensed untreated h drocarbons separately collected during suc periods of interruption are thus utilized to improve the refining operation and at'the same time are sub- )ected to refining treatment in a particularly Thefseparately collected untreated hydrocarbons are, with ad, vantage, introduced into a lfractionating -operation through which the Ahydrocarbon vapors are passed on their way,to -the re-` ining operation, being thereby reva orized and at the same time yassisting in coo ing the v vapors in the fractionating operation. The

fractionating' operation may be controlled to accommodate the variable rate at which such separately collected untreated .hydrocarbons are supplied. l

" The invention will be further described in connection with the accompanying drawings which illustrate, di'agrammatically and con:A ventional1y,.in elevation, apparatus adapted for carrying out the invention, but it is in tended, and will be understood that this more detailed description and illustration of the invention is by way ofcexemplication.

Referring to the drawings, therening operation proper is carriedA out in the tower 1` in which a charge of the'adsorptive catalyst,

for example, fullersl earth of -60 or 60-80 mesh, .is su ported upon Aa tera-minous parti'- tion 2. e hydrocarbon vapors to be refined are supplied through connection" 3,

' the ese catalyst in t e tower 1 either upwardly oi downwardly and discharged through connection 4 to the condenser 5. In normal opera tion, the hydrocarbon vapors passed through the refining tower 1 to the condenser 5are condensed in the condenser 5, the condensate is separated fromuncondensed vapors and gases in receiver 6, the condensed refined product is discharged through connections 7 and 8, un-

condensed vapors and gases are discharged.

through connection 9, and high. boiling polymers and any other material liquefied in .the tower 1 are discharged throughconnection10. When the charge of the adsorptive catalyst in the refining towerl has lost its elfectiveness, valves 11 and` 12 are closed and valves 13 and 14fare opened to by-pass through conlnection 18 tothe condenser 5 the hydrocarbon vapors normally passed through the refining tower, and at the same time the valve 15 is closed andthe valve 16 is opened so thatthe condensed untreated hydrocarbons are separately collected `in the'tank 17 during this in-v terruption of the refining operation. The spent adsorptive catalyst is then discharged from the refining towerand the discharged material replaced with a fresh charge of the adsorptivecatalyst. As soon as thefresh adsorptive catalyst has been supplied to the refining tower, valves `13 and 14 are closed and valves 11 'and 12 are opened to resume passage of the hydrocarbon vapors through the refining tower 1, and valve 16 is closed and valve15 is opened to resume discharge `of the refined product through connection 8.

During the periodof high initial activity of the adsorptive catalyst following resumption of the refining operation, untreated hydrocarbons collected in tank 17 are passed'through the^rening tower 1 in addition to the' hydrocarbon vapors normally passedV therethrough.

.As the high initialactivity ofthe adsorptive catalyst diminishes,'the proportion of such separately collected untreated' hydrocarbons supplied to the refining operation in addition tothelhydrocarbon vapors normally passed therethrough may be diminished or lthe supply of ,such separately collected untreated hydrocarbons may be stopped. such separately collected untreated hydro- .carbons are supplied tothe reining operation may be re lated progressively to decrease the velocity olf vapor travel through the refining tower 1 as the activity of the adsorptive catalyst decreases, or such separately collected untreated hydrocarbons may be supplied 'to the refining operation during the initial peri d of the refining operation while activity ofthe adsor tive catalyst haspassed.

115. The rate at which orptive catalyst is highly active and f this su ply of separately collected untreatedv hydrocarbons stopped after the. high initial Inusualpractice,t e periodof interruption Massese of the 'refining operation necessary to discharge the spent adsorptive catalyst and to replace the discharged material with -fresh material 1s much shorter than the following period during which the refining operation is resumed and the period of high initial ac- .tivity of the fresh adsorptive 4catalyst corresponds approximately with the period of interruption, so that usually the amount of untreated hyrocarbons separately 'collected` during the period of .interruption approximates quite closely the amount necessary to be supplied to the refining operation in addition to the hydrocarbon vapors normally passedy therethrough during the initial period of the I refining operation while` the activity ofthe freshv adsorptive' catalyst supplied during the interruption is high when the refinlng oper-j Iation is resumed.

2 v Q par'atus illustrated, the hydrocarbon vapors In 'carrying out the'.invention in the aptank 17 through connections 21 and 22 by means of pmump 23.L In the fractionating tower 19, the condensed untreated hydrocarbons so introduced are reva orized by heat exchange with the vapors in t e fractionating tower to escape in adm ixture with the uncondensed vapors from the fractionating tower. Thisvaporization at the same time assists in cooling the vapors inthe fractionating tower. The sup? y of condensed u ntreated hydrocarbons rom tank 17 1s regulatedC with respectl to the activity of the adsorptive catalyst in the refining operation; as this regulation would introduce a variable factor into the fractionating operation,ther reluxing'action of the'condensed untreated hydrocarbons so supplied to the u per end of the fractionating tower is supp emented hy some other suitable refluxing control, for example, by the direct introduction of someother refluxing medium throughcnnections 24 and 2 2 by means v'of 1pump 25 or by circulation of water or coo oil through cooling coil v26, and this other relluxin control is regulated to-maintain-(uniform e `fractionating operation. For example, 1n operations to produce gasoline, agasoline `:fraction to be blended with the gasoline productl and relatively inert with respect to the adsorptive catalyst in the refining operation may be supplied through connectlons 24 and 22 at a rate regulated with respect to the l"supply of coni densed untreated material through connections 21 and 22' to equalize the reluxing ef-v i .fect in the fractionating tower 19. A lse -f` arate alternative refluxing medium may supplied through connections 24 and 22, for

. example, while the supply of condensed untreated hydrocarbons through connections 21 l' and 22 is stopped, 0r such separate relux'ing medium may be supplied through connections 24 and 22 ata rate increasing and decreasin with decrease land increase, respectively, o the rate at which such condenseduntreated hydrocarbons are supplied rough connec- 'tions 21 and 22. Material iqueed in the fractionating tower 19 is dischargedthrough connection 27.

It. will be understood that .the cycle of operations just described is repeated as fsuccessive charges of the adsorptive catalyst lose their eli'ectiveness, are discharged and thedischarged material replaced with fresh charges of the adsorptive catalyst.

' I claim:

'1. In the vapor phase refining of hydrocarbons by passage of the hydrocarbon vapors through a charge of an adsorptive catalyst,

vthe improvement which comprises interrupt,

ing the refining operation from time to time to -supply fresh catalyst thereto and, during the period of interruption, condensing and separately collecting untreated hydrocarbons normally passed throughfthe. catalyst, and passing such separatelyl collected hydrocarbons as vapors through the catalyst in addition to the vapors normally passed there through upon resuming the refining o eration aoy after the period of. interruption 'an during the period fof high initiaLactivity of fresh `of hydro-r comprises catalyst supplied to the operation. 2. In the vapor phase refinin carbons, the improvement whic passing the hydrocarbon vapors successively 'through a fractionating operation and an adsorptive catalyst, interrupting'the refinin operation vfrom time to time to supply frcs catalyst and, during the period of interruption, condensing and separately `collectin untreated hydrocarbons normally passe through the catalyst, and introducing'such separately collected hydrocarbons into the vapors in the fractionatng operation upon resuming vthe refining operation after' the period. of interruption and during the period of high initial activity' of fresh catalyst supphed to the -opleratiom such separately collected ydrocarbons are whereby vaporized Aand passedthrough the catalyst j in admixture with the vapors normally.

passed therethrough! In testimony vwhereof, I have `subscribed.

my name.

v FRANK nog 

